Radiant work heating gas burner



Patented Apr. 1, 1952 RADIANT WORK HEATING GAS BURNER John D. Nesbitt,

Sylvania,

and Henry W.

Schramm, Toledo, Ohio, assignors to Surface Combustion Corporation,Toledo, Ohio, a corporation of Ohio Application October 22, 1949, SerialNo. 122,980

4 Claims.

This invention relates to high temperature heating apparatus of the typecomprising elongate work heating burners adapted to be arranged inspaced facing relation to provide between their facing sides a hightemperature heating zone wherethrough work pieces may be passed forrapid heating to elevated temperature; and the general object of theinvention is to provide a burner construction that shall be well adaptedto withstand the elevated temperatures that must necessarily prevail inthe heating zone between the burners.

For a consideration of what we consider to be novel and our invention,attention is directed to the following specification and the claimsappended thereto.

In the drawings,

Fig. 1 is a miniature view in longitudinal side elevation of a heatingapparatus embodying the burners of the present invention.

Fig. 2 is a fragmentary isometric view of one end of a-pair of theimproved burners which are embodied in the heating apparatus shown inFig. l. 1

Fig. 3 is a plan view of the heating side with parts in section of theimproved burner and illustrating how the burners may be supportedbetween supporting standards.

Fig. 4 is a vertical transverse sectional view of the improved burner.

Fig. 5 is a fragmentary plan and sectional View of a detail of theburner.

Fig. 6 is an isometric view of one end of a mandrel used in forming theburner combustion tunnel.

An application of the improved burners is schematically indicated inFig. 1. In this view two of the burners l and l l are arranged invertically spaced relation with their heating sides facing each other todefine between said sides a high temperature heating zone through whichelongate forging stock l2 disposed crosswise of said zone may beadvanced from one end to the other of said zone by appropriate guidingmeans l3. As best shown, in Fig. 3, the two burners may be maintained infixed spaced relation by supporting structure comprising lateralbrackets M at both ends of each of said burners for attachment toupright supporting standards shown in outline. The two burners are ofidentical construction and therefore a detailed description of one willapply to both.

Each burner comprises a slot-type combustion tunnel H in a relativelymassive elongate refractory block I6 which is closely confined in anopen top metal box l9 to constitute a refractory liner within the box.The bottom wall, the side walls and the end walls of the box arerespectively identified by reference numerals 28, 24 and 34. The block[6 will ordinarily be made in the box l9 itself from a castable mix ofrefractory material, and the tunnel I! will ordinarily be formed in themix by a mandrel 26 placed in the box before the mix is placed thereinand removed therefrom after the mix has set. The hardened mix ispermanently held in place in the box [9 by holding members 25 already inthe box before the refractory mix is placed therein, said members eachpreferably comprising an angled strip of expanded or perforated metalspot welded at its longitudinal edges to the side walls of the box.

For the major portion of its length, the facing sides of the tunnel Hare preferably parallel to each other and thereafter diverge rathersharply as indicated at Hi to provide surfaces from which hea s radiatedto the work in the heating zone between facing burners, it beingunderstood that the work will also be heated by the highly heatedcombustion products issuing from the combustion tunnel. The fuel to beburned in the combustion tunnel will ordinarily consist of fuel gaswhich has been admixed with its full complement of air for completecombustion before being introduced into said tunnel in the mannerpresently appearing.

An elongate gas nozzle 20 extends through the bottom wall 28 of the boxIS in longitudinal alinement with the adjacent end of the combustiontunnel ll, the nozzle extending from a longitudinally extending fuelsupply header 22 welded to said wall 28 at opposite lateral sides saidnozzle to form a fluid tight joint where the nozzle, extends throughsaid wall. The nozzle 20 will ordinarily consist of a plurality of rowsof drilled ports 2| of which the ports in the outer rows will ordinarilybe drilled at an angle inclined towards the adjacent boundary surface ofthe tunnel so that the gas issuing from the inclined ports will wipesaid surfaces and thereby accelerate combustion. Fuel gas alreadyadmixed with its full complement of air for complete combustion isdelivered under pressure to one end of the fuel supply header 22 by asupply pipe not shown, the other end of the header being closed by anordinary pipe cap 23.

Due to the high temperature that prevails in the combustion tunnel H,the block 16 as a whole tends to become so highly heated that in theabsence of means for cooling the walls of the metal box I9, said Wallstend to overheat and warp.

To prevent such overheating and warping, the box 19 is surrounded by ajacket casing 21 to provide a water jacket 30 about said box. The jacketcasing 21 also extends about the fuel supply header 22 whereby the fuelnozzle 20 is indirectly maintained relatively cool by conduction of heatto the relatively cool wall of said fuel supply header.

The lower portion of the jacket casing 21 (as' viewed in Fig. 4) iswelded water tight to the lower side of the fuel supply header 22 andsince the latter is alsowelded water tight to the bottom Wall 28 of thebox l9, the header divides the lower portion of the water jacket intoright and left hand portions and of course also imparts rigidity to theburner structure as a whole. That portion of the water jacket at theends of the box I9 is divided into right and left hand portions by abafile plate 35 which extend between the end wall 7 33 of the jacketcasing 27 and the end wall 34 of the box l9. Cooling water from a sourceof supply enters one of the half portions of the water jacket through apipe inlet 36 at one end of the jacket casing 21 and thence flows to theopposite end of said one portion and thence out through a pipe outlet 31and thence through a cross pipe 48 to a pipe inlet 4! for the other halfportion of the water jacket and thence to the opposite end of the latterand thence to Waste through a pipe outlet 42. a

- To protect the heating side of the refractory block from abrasion bythe work being heated elevated Wear rods 3! are welded to andconstitute'part of the connection between the adjacent edges of box sidewall 24 and of the jacket casing side wall. The wear rods 3| preferablyextend a short distance beyond the end walls 33 of the jacket casing 21so that they may be readily alined, if so desired, with work supportingguide rails not shown leading to and from the heating A burnerconstructed as herein shown and described is particularly Well adaptedto Withstand the severe temperature conditions to which it is normallyexposed.

What we claim is:

1. In a gas burner, incombination, a bottom wall, end walls, andparallel side walls together defining an elongate open-top metal box, aone piece refractory block cast in said box in contact with the interiorsurfaces of said box and having a longitudinally extending slot-typecombustion chamber extending from top to bottom centrally of said block,mean including a passage disposed along the back side of said bottomwall and communicating through said bottom wall for supplying combustile mixture to said combustion chamber, and a metallic body embedded insaid block at each side of said combustion chamber and anchored to theadjacent side wall of said box for reinforcing said block and tending tohold it in position in said box, said metallic body comprising anelongate strip of sheet metal having a plurality of apertures extendingtherethrough of a size to permit the mix of which said block is cast topass freely therethrough.

2. In a gas burner, in combination, a bottom wall, end walls, andparallel side Walls together defining an elongate open-top metal box, aone piece refractory block cast in said box in contact with the interiorsurfaces of said box and having a longitudinally extending slot-typecombustion chamber extending from top to bottom centrally of said block,means including a passage disposed along the back side of said bottomwall and communicating through said bottom wall for supplyingcombustible mixture to said combustion chamber, a metallic body embeddedin said block at each side of said combustion chamber and anchored tothe adjacent side wall of said box for reinforcing said block andtending to hold it in position in said box, said metallic bodycomprising a V-shape strip of sheet metal'having a plurality ofapertures extending therethrough of a size to permit the mix of whichsaid block is cast to pass freely therethrough, and the free ends ofsaid strip being welded to the adjacent side wall of said box.

3. In a gas burner, in combination, a bottom wall, end walls, andparallel side walls together defining an elongate open-top metal box, aone piece refractory block cast in said box in contact with the interiorsurfaces of said box and having a longitudinally extending slot-typecombustion chamber extending from top to, bottom centrally of saidblock, means including a passage disposed along the back side of saidbottom wall and communicating through said bottom wall for supplyingcombustible mixture to said combustion chamber, and a metallic bodyembedded in said block at each side of said box anchored thereto forreinforcing said block and tending to hold it in position in said box,said metallic body having a plurality of apertures extendingtherethrough of a size to permit the mix of which said block is cast topass freely therethrough.

4. In a gas burner, in combination, a bottom wall, end walls, andparallel side walls together defining an elongate open-top metal box, aone piece refractory block cast in said box in contact with the interiorsurfaces of said box and having a longitudinally extending slot-typecombustion chamber extending from top to bottom centrally of said block,mean including a passage disposed along the back side of said bottomwall and communicating through said bottom wall for supplyingcombustible mixture to said combustion chamber, and elongate metallicbodies extendin inwardly from said walls and spaced from the side wallsat least at intermediate portions and imbedded in said block ateach-side of said com bustion chamber and anchored to the adjacent sideWall of said box for reinforcing saidblock and tending to hold it inposition in said box.

Number Name Date 1,655,936 Brown Jan! 10,1928 2,220,928 Kienleet a1.Nov. 12, 1940 r 2,333,381 Kelly et a1 Nov.-2, 1943 Hess Jan. 25, 1949

